package org.utils
{   
	
	import flash.display.BitmapData;   
	import flash.display.BlendMode;   
	import flash.display.DisplayObject;   
	import flash.display.Sprite;   
	
	import flash.geom.ColorTransform;   
	import flash.geom.Matrix;   
	import flash.geom.Point;   
	import flash.geom.Rectangle;   
	
	public class HitTestUtil 
	{   
		
		/*  
		该方法返回 碰撞 true/false  
		*/    
		public static function complexHitTestObject( target1:DisplayObject, target2:DisplayObject,  accurracy:Number = 1 ):Boolean   
		{   
			return complexIntersectionRectangle( target1, target2, accurracy ).width != 0;   
		}   
		
		public static function intersectionRectangle( target1:DisplayObject, target2:DisplayObject ):Rectangle   
		{   
			// If either of the items don't have a reference to stage, then they are not in a display list   
			// or if a simple hitTestObject is false, they cannot be intersecting.   
			if( !target1.root || !target2.root || !target1.hitTestObject( target2 ) ) return new Rectangle();   
			
			// Get the bounds of each DisplayObject.   
			var bounds1:Rectangle = target1.getBounds( target1.root );   
			var bounds2:Rectangle = target2.getBounds( target2.root );   
			
			// Determine test area boundaries.   
			var intersection:Rectangle = new Rectangle();   
			intersection.x   = Math.max( bounds1.x, bounds2.x );   
			intersection.y    = Math.max( bounds1.y, bounds2.y );   
			intersection.width      = Math.min( ( bounds1.x + bounds1.width ) - intersection.x, ( bounds2.x + bounds2.width ) - intersection.x );   
			intersection.height = Math.min( ( bounds1.y + bounds1.height ) - intersection.y, ( bounds2.y + bounds2.height ) - intersection.y );   
			
			return intersection;   
		}   
		
		public static function complexIntersectionRectangle( target1:DisplayObject, target2:DisplayObject, accurracy:Number = 1 ):Rectangle   
		{                        
			if( accurracy <= 0 ) throw new Error( "ArgumentError: Error #5001: Invalid value for accurracy", 5001 );   
			
			// If a simple hitTestObject is false, they cannot be intersecting.   
			if( !target1.hitTestObject( target2 ) ) return new Rectangle();   
			
			var hitRectangle:Rectangle = intersectionRectangle( target1, target2 );   
			// If their boundaries are no interesecting, they cannot be intersecting.   
			if( hitRectangle.width * accurracy <1 || hitRectangle.height * accurracy <1 ) return new Rectangle();   
			
			var bitmapData:BitmapData = new BitmapData( hitRectangle.width * accurracy, hitRectangle.height * accurracy, false, 0x000000 );    
			
			// Draw the first target.   
			bitmapData.draw( target1, HitTestUtil.getDrawMatrix( target1, hitRectangle, accurracy ), new ColorTransform( 1, 1, 1, 1, 255, -255, -255, 255 ) );   
			// Overlay the second target.   
			bitmapData.draw( target2, HitTestUtil.getDrawMatrix( target2, hitRectangle, accurracy ), new ColorTransform( 1, 1, 1, 1, 255, 255, 255, 255 ), BlendMode.DIFFERENCE );   
			
			// Find the intersection.   
			var intersection:Rectangle = bitmapData.getColorBoundsRect( 0xFFFFFFFF,0xFF00FFFF );   
			
			bitmapData.dispose();   
			
			// Alter width and positions to compensate for accurracy   
			if( accurracy != 1 )   
			{   
				intersection.x /= accurracy;   
				intersection.y /= accurracy;   
				intersection.width /= accurracy;   
				intersection.height /= accurracy;   
			}   
			
			intersection.x += hitRectangle.x;   
			intersection.y += hitRectangle.y;   
			
			return intersection;   
		}   
		
		
		protected static function getDrawMatrix( target:DisplayObject, hitRectangle:Rectangle, accurracy:Number ):Matrix   
		{   
			var localToGlobal:Point;;   
			var matrix:Matrix;   
			
			var rootConcatenatedMatrix:Matrix = target.root.transform.concatenatedMatrix;   
			
			localToGlobal = target.localToGlobal( new Point( ) );   
			matrix = target.transform.concatenatedMatrix;   
			matrix.tx = localToGlobal.x - hitRectangle.x;   
			matrix.ty = localToGlobal.y - hitRectangle.y;   
			
			matrix.a = matrix.a / rootConcatenatedMatrix.a;   
			matrix.d = matrix.d / rootConcatenatedMatrix.d;   
			if( accurracy != 1 ) matrix.scale( accurracy, accurracy );   
			
			return matrix;   
		}   
		
	}   
	
}